#define THREAD_NEW (threads && hdr->collapsed && hdr->num_hidden > 1 && mutt_thread_contains_unread (ctx, hdr) == 1)
#define THREAD_OLD (threads && hdr->collapsed && hdr->num_hidden > 1 && mutt_thread_contains_unread (ctx, hdr) == 2)
#define THREAD_NEW (threads && hdr->collapsed && hdr->num_hidden > 1 && mutt_thread_contains_unread (ctx, hdr) == 1)
#define THREAD_OLD (threads && hdr->collapsed && hdr->num_hidden > 1 && mutt_thread_contains_unread (ctx, hdr) == 2)